In this document, a “catheter lead” or “electrode lead” refers to any catheter to be affixed within the body of a human being or an animal, or any type of electrode lead for at least temporary intracorporal fixation. Examples include catheters for supplying fluids or objects into bodily cavities or vessels, or for draining fluids from these, pacemaker electrode leads, shock electrode leads, vascular stimulation leads, etc.
Many such catheter leads or electrode leads have long been known, and an extremely diverse variety of these are commercially available. When developing the technology for pacemakers and cardioveters, special attention was paid to the secure fixation of the electrode leads directly on the heart tissue to be stimulated or defibrillated, and a variety of different fixation mechanisms were developed to achieve this purpose.
Vascular electrodes, such as coronary sinus electrodes, must be very thin and flexible to allow them to be implanted in the desired target veins of the heart. These electrodes must be securely anchored in the target regions. In addition, it is also desirable from a clinical point of view for the electrodes to then be explantable (removable) at a later time. Passive fixations, such as, e.g., a distal thread, a helix, or other preshapings of the electrode body continue to result in dislocation rates of 10%-15%. What is advantageous about these electrodes is their subsequent explantation capability without complications. Actively affixable electrodes having a distal expansion element do provide effective acute fixation, but also tend to generate a positive-fit attachment of the electrode to the wall of the vein. As a result, they are generally no longer explantable.